hello all.... i have used DIY Rocks and i was / am pretty happy with the rocks ... you can get the shape you like and desired aquascape.... the cons of this kind of rocks are 1) they are heavy 2) requires loooooong curing time, mine took around 4-5 months to cure.. may be more dont remember it now..

currently i am using Fiber rocks and i am very happy with the same got the required structure that i planned and are light weight...

Bacterial growth is not much in the fiber rocks but i dont mind as i used all the old fiji LR from the old tank in the sump as filteration.. and all DIY rocks donated to LFS and he is currently using it in his display tank ..

regarding sansibar rocks they are OK to use it and are quite porus...

but i would say if this is a life time and reef setup either get cured natural LR or go with fiber rocks and seed the sump with LR from hobbyist tank..

if you need recipe of the DIY rock you can go through my old posts in my thread .. or buzz me up anytime hope this helps..